Intrathoracic and pulmonary blood volume during CO2-pneumoperitoneum in humans

Background : Induction of CO₂-pneumoperitoneum may have significant effects on systemic and pulmonary haemodynamics. We hypothesized, that intrathoracic (ITBV) and pulmonary blood volume (PBV) are affected during intra-abdominal CO₂-insufflation, which may be pronounced by positional changes of the patient.
Methods : Sixteen anaesthetized patients were studied before, during and after CO₂-pneumoperitoneum for laparoscopic cholecystectomy. A dye indicator technique was used to assess ITBV and PBV. In addition, gas exchange and haemodynamics were recorded.
Results : In the supine position, induction of CO₂-pneumoperitoneum had no effects on ITBV, PBV and cardiac output. Mean systemic arterial pressure increased from 10.9±1.5 kPa (82±11 mmHg) to 12.7±1.5 kPa (95±11 mmHg, P<0.01). In the reverse Trendelenburg position ITBV decreased from 19.8±5.1 ml . kg^-1 to 16.7±3.7 ml . kg¹ ( P <0.05) during CO₂-insufflation, but increased to control values after 20 min. PBV decreased from 4.2±1.2 ml . kg^-1 to 3.4±1.1 ml . kg^-1 (P<0.05) and remained decreased during CO₂-pneumoperitoneum. Calculated venous admixture was unchanged throughout the study. Deflation of CO₂-pneumoperitoneum increased ITBV (22.4±5.2 ml . kg^-1, P<0.05) and cardiac output above control values.
Conclusions : In anaesthetized-paralyzed patients in the reverse Trendelenburg position intra-abdominal CO₂-insufflation is associated with significant alterations of ITBV and PBV. The release of CO₂-pneumoperitoneum is associated with a re-distribution of blood into the thorax.     

A bolus dose of 1.5 mg/kg amrinone effectively improves low cardiac output state following separation from cardiopulmonary bypass in cardiac surgical patients

Background : The aim of this study was to evaluate the efficacy of 1.5 mg/kg bolus of amrinone on low cardiac output (CO) state following emergence from cardiopulmonary bypass (CPB) in cardiac surgical patients.
Methods : Immediately after emergence from CPB, 14 patients with a cardiac index (CI) less than 2.2 l min^-1 m^-2 despite administration of inotropes and nitroglycerin, received 1.5 mg/ kg amrinone over 3 min without changing catecholamine infusion rates (amrinone group). Hemodynamics and left ventricular short axis views with transesophageal echocardiography were recorded at baseline, 3, 5, and 10 min following amrinone administration. Left ventricular filling volumes were maintained constant by volume reinfusion from the CPB reservoir. We matched the data of the amrinone group with the other 14 patients who did not receive amrinone (non-amrinone group) to evaluate the efficacy of amrinone in low CO state.
Results : At baseline, CI (1.8±0.1 1 min^-1 m^-2) in the amrinone group was significantly lower than CI (3.0±0.2) in the non-amrinone group. Following amrinone administration, CI and velocity of circumferential fibershortening corrected for heart rate (Vcfc) significantly increased, and systemic vascular resistance index and pulmonary vascular resistance index significantly decreased from the baseline within 10 min without changes in heart rate, mean arterial blood pressure, or pulmonary artery occlusion pressure, and became equivalent with those of the non-amrinone group.
Conclusions : A 1.5 mg/kg amrinone loading dose to patients in a low CO state, despite catecholamine therapy immediately after emergence from CPB, effectively improves ventricular function when loading conditions are maintained constant.     

Comparison of subhypnotic doses of thiopentone vs propofol on the incidence of postoperative nausea and vomiting following middle ear surgery

Background : Middle ear surgery is associated with a high incidence of emetic sequelae and propofol has been reported to have antiemetic activity in subhypnotic doses.
Methods : In a double-blind, randomized study, the patients received either thiopentone 1.0 mg.kg^-1 (n=26) or 0.5 mg.kg^-1 propofol (n=26) at the end of middle ear surgery under isoflurane-N₂O-fentanyl-vecuronium anaesthesia. Trained nurses, unaware of the group assignment, assessed postoperative nausea, retching and vomiting up to 24 h after the end of anaesthesia. Droperidol 10μg.kg^-1 was used as a "rescue" antiemetic.
Results : The main result was that the patients in the propofol group did not suffer from retching and vomiting (R&V) during the first 6 h, whereas these symptoms occurred in 46% ( P <0.001) of the patients in the thiopentone group. The patients in the propofol group needed significantly less droperidol during the first 24 h (mean number of doses 0.39 ± 0.57 (SD)) than the patients in the thiopentone group (1.35 ± 1.47, P <0.005). Treatment with propofol was a predictor for lowered incidence of R&V, as well as male gender and negative history of motion sickness.
Conclusion : Propofol at a subhypnotic dose of 0.5 mg.kg^-1 provides prophylaxis against retching and vomiting for the first 6 h postoperatively after middle ear surgery. The incidence of nausea was not reduced by propofol.     

Central venous oxygen saturation for the diagnosis of low cardiac output in septic shock patients

Background: Simple diagnostic tests are needed to screen septic patients for low cardiac output because intervention is recommended in these patients. We assessed the diagnostic value of central venous oxygen saturation in the superior vena cava (ScvO₂) for detecting low cardiac output in patients with septic shock.
Methods: We conducted a prospective observational study in three general intensive care units (ICUs) of adult patients with septic shock, who were to have a catheter inserted for thermodilution measurement of cardiac index (CI_TD). Paired measurements of CI_TD and central venous oximetry values were obtained when the clinician first measured CI_TD.
Results: We included 56 patients with septic shock and a mean sequential organ failure assessment score of 12 (range 3–20). Baseline CI_TD was 3.5 l/min/m² (1.0–6.2) and ScvO₂ of 70% (33–87). The best cut-off of ScvO₂ for CI_TD>2.5 l/min/m² ( n =42) was a value ≥64% with positive and negative predictive values of 91% (95% confidence interval 79–98) and 91% (59–100), respectively. The diagnostic values were not improved by using instead central venous O₂ tension or the difference between arterial and central venous O₂ saturation.
Conclusions: This prospective, observational study found that a ScvO₂ measurement of ≥64% indicated CI_TD>2.5 l/min/m² in ICU patients with septic shock.     

A comparison of the effects of fentanyl and propofol on left ventricular contractility during myocardial stunning

Background : The intravenous anaesthetic propofol has been shown to possess free radical scavenging activity and calcium channel blocking effects in a number of in vitro models. We decided to compare the effects of propofol with those of fentanyl on myocardial contractility during and after ischaemia to determine whether propofol could protect the heart and improve recovery of ventricular contractile function in open-chested dogs.
Methods : Twenty adult beagles were acutely instrumented, under halothane anaesthesia, to measure ECG; aortic, left ventricular pressures; cardiac output; coronary flow; and segmental lengths in the regions perfused by the left anterior and left circumflex coronary arteries. After surgery and a stabilisation period halothane anaesthesia was terminated and fentanyl (100 μg. kg^-1 bolus followed by 2 μ.kg^-1·min^-1 infusion; n=10) or propofol (5 mg. kg^-1 bolus followed by 0.3 mg· kg^-1 min^-1 infusion; n=10) anaesthesia commenced. After a stabilisation period the LAD coronary artery was occluded for 10 min and then reperfused for 3 h. Measurements were taken throughout the protocol.
Results : We found no significant difference in recovery of contractile function between propofol and fentanyl as assessed by normalised preload recruitable work area (50±10 vs 47±16%), normalised systolic shortening (36±12 vs 48±14%) and peak left ventricular dP/dt (1665±276 vs 1846±151 mmHg.s^-1) at the end of reperfusion.
Conclusion : We conclude that at the concentration used in this study propofol shows no improvement in contractility during "stunning" when compared to fentanyl.     

Correlation of Nuclear Morphometry and Immunostaining for p53 and Proliferating Cell Nuclear Antigen in Transitional Cell Carcinoma of the Bladder

Background :
In an attempt to determine the biological significance of nuclear morphometric findings, measurements of mean nuclear volume (MNV) and nuclear roundness factor (NRF) were compared to the immunoreactivityof p53 expression and proliferating cell nuclear antigen (PCNA) in human bladder cancer.
Methods :
MNV and NRF were measured using stereological methods. Expression of p53 and PCNA were determined by immunohistochemical staining. Specimens from 111 patients with previously untreated bladder cancer were analyzed.
Results :
The mean MNV was 235.8 ± 1 33.6 μm³ for the 81 patients with p53-labeling index (LI) less than 10% and 337.2 ± 141.0 μn³ for the 30 patients with p53 LI greater than 10% (P = 0.008). There was Resign if icant correlation between NRF and expression of p53. The mean MNV was 220.1 ± 1 20.5 μm³ for the 67 patients with PCNA LI less than 28% (the mean value of PCNA LI) and 328.9 ± 149.2 μm³ in 44 patients with PCNA LI greater than 28% (P= 0.0001). The mean NRF was 80.7 ± 4.2 for the 67 patients with PCNA LI less than 28%, and 82.3 ± 3.4 for the 44 patients with PCNA LI more than 28% (P= 0.04). Conclusion: Nuclear morphometric findings may reflect the proliferative potential of cancer eel Is of the bladder, as indicated by findings of immunostaining for p53 and PCNA.     

The combination of external high-frequency oscillation and pressure support ventilation in acute respiratory failure

Background: Effective gas exchange can be maintained in animals by using external high-frequency oscillation (EHFO). The present study evaluates the effect of relatively long-term duration EHFO combined with pressure support ventilation (PSV) in patients with acute respiratory failure.
Methods: Twelve patients were ventilated with EHFO combined with PSV for 8 h at 60 oscillations min^-1, with a cuirass pressure of 36 cm H₂O: -26 to +10 cm H₂O (27 mm Hg: -19.5 to +7.5 mm Hg) and an inspiratory-to-expiratory ratio of 1: 1. Blood gas values and hemodynamic parameters were measured. Results: Significant increases were noted in cardiac index (3.0±0.7 to 3.2±0.7 1 min^-1 m^-2, P < 0.05) and stroke volume index (32±14 to 35±13 ml m^-2, P < 0.05) without changes in pulmonary artery wedge pressure at 1 h after EHFO. PaO₂(kPa)/FiO₂ and PaCO₂ improved from 21.9±7.5 to 26.8±8.0 ( P < 0.05) at 2 h and from 6.9±1.7 to 6.1±0.9 kPa ( P < 0.01) at 30 min after EHFO, respectively. Breath sounds could be heard well throughout the lung fields after institution of EHFO. The mucous rales also decreased.
Conclusions: As a method of ventilation for patients with acute respiratory failure, EHFO combined with PSV may have potential advantages over conventional mechanical ventilation when drainage of secretions is facilitated. Beneficial effects of EHFO may appear after several hours.     

Comparison of body temperature changes during laparoscopic and open cholecystectomy

Background: Prevention of hypothermia during abdominal surgery by insulating or heat-transferring methods has been the subject of numerous investigations. This study approaches the problem from a less discussed point of view, i.e. the effect of different surgical techniques on body temperature changes.
Methods: Body temperature was measured at 3 core and 6 skin points in 40 patients scheduled for cholecystectomy through open laparotomy or laparoscopy with pneumoperitoneum created and maintained with unwarmed carbon dioxide (CO₂) insufflation. End-tidal CO₂ was kept constant by adjustments of respiratory frequency. Anaesthesia, intravenous infusions, and draping of the patients were standardized.
Results: During the first 1 h of anaesthesia core temperatures decreased approximately by 0.7˚C and distal skin temperatures increased by 7˚C in both groups. At the end of surgery heat balance was similar in both groups. An increase of 2.5 1 min^-1 in respiratory minute volume was needed to control end-tidal CO₂ levels in the laparoscopy group during pneumoperitoneum, which was maintained with a CO₂ flow of 1.2 l-min^-1 through the abdominal cavity.
Conclusion: Laparoscopic technique with unwarmed carbon dioxide insufflation does not offer any advantage in terms of body temperature changes when compared to open surgery.     

Platelet concentrates transfusion in cardiac surgery and platelet function assessment by multiple electrode aggregometry

Background: Platelet dysfunction contributes to the pathophysiology of bleeding complications during and after cardiac surgery. In most surgical institutions, no peri-operative point-of-care monitoring of platelet function is used. We evaluated the usefulness of the Multiplate^® platelet function analyser based on impedance aggregometry for identifying groups of patients at a high risk of transfusion of platelet concentrates (PC).
Methods: Platelet function parameters were determined in 60 patients before and after routine cardiac surgery. Impedance aggregometry measurements were performed on Multiplate^® using ADP (ADPtest), collagen (COLtest) and thrombin receptor activating peptide (TRAPtest) as platelet activators. The correlations between the aggregometry results and the transfusion of PC were calculated. The results of the aggregation tests were also divided into tertiles and the differences in PC transfusion between the low and the high tertile were assessed.
Results: Low aggregometry delimited groups of patients with significantly higher PC transfusion. In the receiver operating characteristic curve, low pre-operative aggregation in the ADPtest identified patients with high total transfusion of PC (area under the curve 0.74, P =0.001), while the ADPtest performed at the end of the operation identified patients with high PC transfusion on the intensive care unit (ICU) (area under the curve 0.76, P =0.002).
Conclusions: Near-patient platelet aggregation may allow the identification of patients with enhanced risk of PC transfusion, both pre-operatively and upon arrival on the ICU.     

Effect of inhaled nitric oxide on venous admixture depends on cardiac output in patients with acute lung injury and acute respiratory distress syndrome

Background: It has been shown that inhaled nitric oxide (NO) reduces intrapulmonary venous admixture (Q_VA/Q_T) and improves oxygenation in patients suffering from acute respiratory distress syndrome (ARDS). The change in Q_VA/Q_T during NO inhalation varies individually. Factors known to influence the respiratory response to NO are the NO conceritration and the level of shunt before NO administration. Other factors that may modify the effect on gas-exchange during NO breathing are unknown.
Methods: We studied the effect of 40 ppm inhaled NO on pulmonary gas-exchange and haemodynamics in 37 patients with acute lung injury (ALI) and ARDS, respectively, and factors that may influence the respiratory response to NO.
Results: Inhalation of 40 ppm NO produced a decrease in mean pulmonary artery pressure (MPAP) from 33.1±7.2 to 30.2±6.8 (mean±SD) mmHg (P<0.0001) while pulmonary artery wedge pressure (PAWP), cardiac output and mean arterial pressure remained constant. Change in Q_VA/Q_T during NO inhalation depended on the preinhalation cardiac output and had no association with mixed venous oxygen tension, MPAP-PAWP, and Q_VA/Q_T before NO delivery. Q_VA/Q_T decreased in 26 patients (group 1) and increased in 11 patients (group 2) during NO inhalation. In group 1, cardiac output was lower than in group 2 (8.6 vs. 12.2 1-min^-1; P<0.0005).
Conclusion: We conclude that the change in venous admixture during inhalation of 40 ppm NO depends on cardiac output. If preinhalation cardiac output is high, 40 ppm NO can adversely affect gas exchange in patients with ALI and ARDS.     

Cardiac output monitoring by impedance cardiography in cardiac surgery

The cardiac output monitoring by impedance cardiography, NCCOM3, was evaluated in adult patients (n = 12) who were subjected to coronary artery bypass grafting. Values of cardiac output measured by impedance cardiography were compared to those by the thermodilution method. Changes of base impedance level used as an index of thoracic fluid volume were also investigated before and after cardiopulmonary bypass (CPB). Correlation coefficient (r) of the values obtained by thermodilution with impedance cardiography was 0.79 and the mean difference was 1.29 +/- 16.9 (SD)% during induction of anesthesia. During the operation, r was 0.83 and the mean difference was -14.6 +/- 18.7%. The measurement by impedance cardiography could be carried out through the operation except when electro-cautery was used. Base impedance level before CPB was significantly lower as compared with that after CPB. There was a negative correlation between the base impedance level and central venous pressure (CVP). No patients showed any signs suggesting lung edema and all the values of CVP, pulmonary artery pressure and blood gas analysis were within normal ranges. From the result of this study, it was concluded that cardiac output monitoring by impedance cardiography was useful in cardiac surgery, but further detailed examinations will be necessary on the relationship between the numerical values of base impedance and the clinical state of the patients.     

Effect of esmolol on the heart rate, arterial pressure and electrocardiographic changes during laryngomicroscopy

Background: Laryngomicroscopy causes considerable haemo-dynamic and ECG changes and therefore requires high doses of anaesthetic agents, which prolong recovery. In this double-blind randomized work, we studied the effect of esmolol, a short-acting beta-adrenergic receptor-blocking agent, on haemodyn-amic and ECG changes during laryngomicroscopy under thio-pental-alfentanil-isoflurane-suxamethonium anaesthesia.
Methods: Forty ASA class I-II patients (mean age 43±11 yr) were allocated to receive either esmolol 1 mg·kg^-1+200 μg·kg^-1· min^-1 (the esmolol group) or saline (the control group). Heart rate and arterial pressure were measured non-invasively and ECG was analyzed with the aid of a microcomputer. Comparisons between the groups were performed using two-way analysis of variance with repeated measures and the Student's t -test.
Results: In the presence of esmolol, neither the heart rate nor the QTc interval of the ECG increased significantly when com pared with the baseline values, with the exception that the QTc interval was increased after intubation. The increase in arterial pressure after insertion of the operating laryngoscope was not prevented in esmolol-treated patients. No cardiac arrhythmias occurred in either of the groups.
Conclusions: On the basis of the present study, esmolol-bolus +infusion during alfentanil-isoflurane anaesthesia in healthy, middle-aged patients is a useful treatment in circumstances where an increase of the heart rate, prolongation of the QTc interval and cardiac arrhythmias should be avoided.     

A new, minimally invasive technique for measuring cardiac index: clinical comparison of continuous cardiac dynamic monitoring and pulmonary artery catheter methods

To assess the utility of a relatively simple bedside method of estimating cardiac index during major surgery or in the intensive care unit, we conducted a prospective study in patients undergoing elective cardiac bypass surgery where a pulmonary artery catheter was inserted as part of routine monitoring. The cardiac index was estimated using standard techniques and compared with estimates from continuous cardiac dynamic monitoring using heartsmart ^® software. Two hundred and seventy sets of measurements were suitable for comparison. The mean bias (95% limits of agreement), for the pre-bypass cardiac index was −0.09 (−1.26 to 1.08) l.min⁻¹.m⁻², and post-bypass was 0.12 l.min⁻¹.m⁻² (−1.32 to 1.56). These results suggest that continuous cardiac dynamic monitoring using heartsmart ^® is sufficiently accurate for assessment of haemodynamic variables in critically ill patients, facilitating goal-directed therapies.     

The Effect of Surgical Stress on Haemodynamics During Neurolept Anaesthesia

The influence of surgical stress on haemodynamics during neurolept anaesthesia (NLA) was studied in ten patients, while they were awake, under anaesthesia prior to surgery and peroperatively. Systemic arterial, pulmonary arterial, right atrial and pulmonary capillary wedge pressures, as well as cardiac output (Q_t), arterial oxygen content and mixed venous oxygen content, were measured. Systemic and pulmonary vascular resistances, arterial-venous oxygen content difference (AVD), oxygen consumption (v_o2 and cardiac index (CI) were calculated.
On institution of anaesthesia, CI fell from 2.8 ±.11 /min. m² to 2.5±0.2 l /min.m² and systolic arterial pressure (SBP) fell from 13.4±0.5 kPa to 10.2±0.3 kPa. During surgery CI rose to 3.3±0.1 1/min.m² and SBP rose to 15.7±0.6 kPa. Prior to anaesthesia, AVD was 40.2±0.2 ml/l Under anaesthesia prior to surgery, AVD did not change, but v_O2 declined from 207±13 ml/min to 171±10 ml/min. During surgery, AVD fell to 30.5±0.3 ml/l, while V_o2 remained unchanged.
It is concluded that NLA has a direct metabolic depressant effect and, in association with surgery, is accompanied by hyperkinetic circulation.     

Cardiac surgery patients present considerable variation in pre-operative hemodynamic variables

Background: It is essential to control hemodynamics in cardiac surgery. Patients are often monitored extensively in order to optimize hemodynamic performance. However, pre-operative values are normally unknown. Furthermore, hemodynamic goals may seem arbitrary and the lack of an evidence-based consensus may lead to both under- and over-treatment. The aim of this study was to evaluate the variables most commonly used for hemodynamic guidance in the post-operative period.
Methods: Ten patients scheduled for elective cardiac surgery were followed with invasive hemodynamic monitoring the night before surgery. All data were recorded automatically and electronically.
Results: We found considerable inter-patient differences and intra-patient variation. The greatest intra-patient variation was found in the cardiac index (CI), ranging from 1.9 to 5.3 l/min/m². Four patients had periodic CI <2.4 l/min/m². Eight patients showed SpO₂ values ≤92, four of them in more than 15% of the observations. Six patients had an SvO₂ <70% in more than 40% of the observations and two an SvO₂<64% in more than 20% of the observations.
Conclusions: This study is unique because hemodynamic reference data in cardiac surgery patients have not been published previously. The intra-patient variations were unexpectedly high in most hemodynamic variables and demonstrate the difficulties of using hemodynamic parameters as a guidance for treatment and indicate that goal-oriented therapy using currently accepted values may result in over-treatment in some patients.     

Contradictory effects of dopamine at 32°C in pigs anesthetized with ketamine

Background: In critically ill patients who were surface cooled to 332C, we have observed that dopamine sometimes causes a substantial decrease in blood pressure. The present study was designed to compare the effects of dopamine in normothermia to those seen after surface cooling to 32C.
Methods: Seven pigs with a mean body weight of 21 kg were anesthetized with ketamine and muscle relaxation was induced with pancuronium. They were mechanically ventilated and given dopamine infusions (5 and 12 μg · kg^-1 min^-1) in normothermia and after surface cooling by cold water immersion to a central blood temperature of 320C (range 31.6–32.6C).
Results: In normothermia, dopamine at a dose of 5 μg · kg^-1 min^-1 increased mean arterial blood pressure (MAP) by 16% ( P < 0.01) and cardiac output (CO) by 9% ( P =0.051); at 12 μg kg^-1 min^-1 dopamine increased MAP by 26% ( P < 0.01) and CO by 18% ( P < 0.01). In hypothermia, MAP and CO did not change at an administration rate of 5 μg kg^-l · min^-1; at 12 μg · kg^-1 min^-1 CO was unchanged but MAP was significantly reduced by 15% ( P < 0.01).
Conclusion: Dopamine increased CO and MAP in normothermia but not at 32C, where there was even a significant reduction of MAP in this porcine model.     

Atelectasis and pulmonary shunting during induction of general anaesthesia - can they be avoided?

Background: Gas exchange is regularly impaired during general anaesthesia with mechanical ventilation. A major cause of this disorder appears to be atelectasis and consequently pulmonary shunt. After re-expansion, atelectasis reappears very slowly if 30% oxygen in nitrogen is used, but much faster if 100% oxygen is used. The aim of the present study-was to evaluate if early formation of atelectasis and pulmonary shunt may be avoided if the lungs are ventilated with 30% oxygen in nitrogen instead of 100% oxygen during the induction of general anaesthesia.
Methods: Twenty-four adult patients with healthy lungs scheduled for elective surgery were investigated. During induction of anaesthesia, the lungs were manually ventilated via a face mask, using either 30% oxygen in nitrogen (group 1, n=12) or 100% oxygen (group 2, n=12). Atelectasis was estimated by computed x-ray tomography and ventilation-per-fusion distribution with the multiple inert gas elimination technique, both awake and during general anaesthesia with mechanical ventilation.
Results: No atelectasis was present in the awake subjects. After induction of anaesthesia, the mean amount of atelectasis was minor (0.2±0.4 cm²) in group 1 and considerably greater (8.0±8.2 cm²) in group 2 ( P <0.001). The pulmonary shunt was 0.3±0.7% of cardiac output in the awake subjects. This value increased to 2.1±3.8% in group 1 and to 6.5±5.2% in group 2 ( P <0.05). The indices of V_A/Q mismatch showed no difference between the two groups.
Conclusion: During induction of general intravenous anaesthesia in patients with healthy lungs, gas composition plays an important role for atelectasis formation and the establishment of pulmonary shunt. By using a mixture containing 30% oxygen in nitrogen, the early formation of atelectasis and pulmonary shunt may, at least in part, be avoided.     

Accuracy and reliability of continuous blood glucose monitor in post-surgical patients

Background: The STG-22^™ is the only continuous blood glucose monitoring system currently available. The aim of this study is to determine the accuracy and reliability of the STG-22^™ for continuously monitoring blood glucose level in post-surgical patients.
Methods: Fifty patients scheduled for routine surgery were studied in surgical intensive care unit (ICU) of a university hospital. After admission to the ICU, the STG-22^™ was connected to the patients. An attending physician obtained blood samples from a radial arterial catheter. Blood glucose level was measured using the ABL^™800FLEX immediately after blood collection at 0, 4, 8, and 16 h post-admission to the ICU (total of 200 blood glucose values).
Results: The correlation coefficient ( R ²) was 0.96. In the Clarke error grid, 100% of the paired measurements were in the clinically acceptable zone A and B. The Bland and Altman analysis showed that bias±limits of agreement (percent error) were 0.04(0.7)±0.35(6.3) mmol (mg/dl) (7%), −0.11(−2)±1.22(22) (15%) and −0.33(−6)±1.28(23) (10%) in hypoglycemia (<70(3.89) mmol (mg/dl), normoglycemia (3.89(70)–10(180) mmol (mg/dl), and hyperglycemia (>10(180) mmol (mg/dl), respectively.
Conclusions: The STG-22^™ can be used for measuring blood glucose level continuously and measurement results are consistent with intermittent measurement (percentage error within 15%). Therefore, the STG-22^™ is a useful device for monitoring in blood glucose level in the ICU for 16 h.     

Continuous cardiac output measurements in the perioperative period

Management of critically ill patients is based on knowledge of fundamental physiologic variables. Automatized and continuous measurement of these variables is preferable. A new system based upon the thermodilution method has been developed to measure cardiac output automatically and continuously. We evaluated the system in the potentially unstable perioperative period with possible great and rapid changes in cardiac output. Twenty patients, scheduled for open heart or abdominal aortic aneurysm surgery, were included in the study, which was approved by the local ethical committee. The patients were monitored up to 30 hours. At random intervals five, iced, bolus thermodilution cardiac output (BCO) determinations were made and compared to the continuous cardiac output measurements (CCO). Two hundred and thirty-one pairs of data were obtained. The cardiac outputs ranged from 2.5–14.9 1-min^-1. The absolute bias was 0.31 1-min^-1 (95% limits of agreement—1.4 1-min^-1 to 2.0 1-min^-1). The mean relative error was 4.7% with a standard deviation of the relative error of 15.4%. The linear regression was represented by: CCO= 1,1352-BCO—0.36. The correlation coefficient R was 0.90 ( P <0.001). In conclusion, the CCO measurement technique is a promising clinical method. The method is straightforward, requires no calibration, is independent of vascular geometry and measures with its limitations volumetric flow. Finally automatic and continuous patient monitoring provides more information and has potential to reveal previously undetected haemodynamic events.     

Central cardiovascular and oxygen variables during haemorrhage in the pig

Background: We evaluated the ability of the standards issued by the Danish Society of Anaesthesiologists to reflect a blood loss.
Methods: In 9 pigs bled (0–24 ml kg^-1) and retransfused (to 28 ml kg^-1) during halothane anaesthesia, central cardiovascular, thoracic electrical impedance (TI), oxygen, acid-base and temperature variables were recorded.
Results: With the recommendation for minor surgery (mean arterial pressure (MAP) and heart rate (HR)), the correlation to the blood loss was 0.74 ( P < 0.001) and with that for major surgery (MAP, HR, central venous pressure (CVP) and rectal temperature (Temp_r)) it was 0.79 ( P < 0.001). With the recommendation for extensive surgery (MAP, HR, CVP, pulmonary artery catheter variables and the central-peripheral temperature difference (ΔTemp_r-t)), the correlation was 0.84 ( P < 0.001). Non-invasive monitoring (MAP, HR, ΔTemp_r-t TI and near-infrared spectroscopy of the brain (S_invosO₂)) was only slightly better than basal monitoring (r=0.76, P < 0.001). However, adding arterial base excess (BE), TI and peripheral temperature (Temp_t) to the recommendation for major surgery resulted in a correlation of 0.87 ( P < 0.001), while adding BE and TI to the recommendation for extensive surgery raised correlation to only 0.88 ( P < 0.001).
Conclusion: When the recommendations were followed the correlation to the blood loss ranged from 0.74–0.84. However, with the recording of MAP, HR, CVP, ΔTemp_r-t, BE and TI a correlation of 0.87 was achieved, indicating that a pulmonary artery catheter may not be in need for patients undergoing surgical procedures with expected haemorrhage.